1. Field of the Invention
The present invention relates to a flat panel display (FPD). More particularly, the present invention relates to an FPD having an adjustable load.
2. Description of Related Art
In an FPD, two sets of perpendicular address lines are used to control pixels arranged in array, so as to display images. Among various display control modes, scan lines and data lines perpendicular to each other are most commonly employed, and the scan lines and the data lines define a plurality of pixels. Each of the scan lines is turned on sequentially, so as to switch on or switch off corresponding switching elements and allow signals transmitted by each of the data lines to be written into the pixels. Thereby, the state of the corresponding pixels can be changed, and the images displayed can be controlled.
Even though the FPD technology gradually tends to be mature, defects unavoidably occur during the fabrication of a display panel. Besides, both the scan lines and the data lines cross through the entire display panel, and therefore the significant total length of the scan lines and the data lines easily results in broken lines. When the scan lines and the data lines formed on a base are broken, parts of the pixels cannot be operated (i.e., line defects). Hence, it is necessary to repair the broken lines, or the display panel is discarded. In addition, it is rather difficult to fabricate the display panel without generating any defects merely by improving the manufacturing process. As a result, techniques of repairing the defects formed in the display panel turn out to be indispensable. According to the pertinent art, defects of the display panel are frequently repaired by laser welding and/or laser cutting.
A conventional FPD not only has a plurality of scan lines and a plurality of data lines perpendicular to each other but also has a rescue unit frequently equipped with a plurality of rescue lines. Under normal circumstances, the rescue lines extend across but not electrically connect the data lines or the scan lines. Nonetheless, when the data lines are damaged, the rescue lines are used for repairing the data lines. For instance, when a damaged data line on the FPD is detected, two ends of the damaged data line and two of the rescue lines crossing the two ends of the damaged data line can be welded respectively, such that the damaged data line is electrically connected with the rescue unit through the rescue lines and is then repaired. In some cases, the rescue unit can further have a buffer element for repeating received signals and transmitting the repeated signals in the original signal levels.
However, different broken positions of the data lines result in different loads, such that weak bright lines or weak dark lines generate. For example, the farther a distance from a broken position of a data line to an initial position where the data signals are transmitted is, the greater the load caused by the data line is; the closer the distance from the broken position of the data line to the initial position where the data signals are transmitted is, the less the load caused by the data line is. Both the weak bright line and the weak dark line negatively affect the quality of images which are displayed on the FPD. To resolve said issue, a fixing resistor is often electrically connected with the buffer element, so as to mitigate the influence posed by different loads due to the different broken positions of the data lines.
With the increasing dimension of the FPD, however, the length of the data lines on the display panel becomes greater and greater. As such, the issue with respect to different loads due to the different broken positions of the data lines can no longer be effectively resolved by disposing the fixing resistor as discussed above. If different fixing resistors are respectively disposed according to the different broken positions of the data lines, complexity of product and material management is raised, and so are the inventory costs and the entire production costs. Therefore, it has been proposed that the buffer element is electrically connected with a variable resistor or capacitor. Based on different broken positions of the data lines, the load can be tuned by utilizing the variable resistor or capacitor, and the weak bright line or the weak dark line caused by different loads (due to the different broken positions of the data lines) can be better prevented.
Notwithstanding the above, stability and reliability of the display quality are reduced because tolerance of manufacturing passive elements including the variable resistor or capacitor cannot be neglected. Moreover, additionally passive elements are required, and therefore manufacturers should afford additional costs when manufacturing the entire product. Further, an additional process is necessitated by electrically connecting the passive elements to a circuit board, which is unfavorable to reduction of costs, simplification of production, and integration of fabricating processes.
As a result, it has become one of the major concerns to provide an FPD in which broken lines can be repaired and load can be tuned properly upon different broken positions of the data lines. Thereby, quality of repairing broken lines in the FPD can be improved, elements can be further integrated, fabrication can be simplified, and manufacturing costs can be lowered down.